1. Field of the Invention
This invention relates generally to the drilling of deep wells such as for the production of petroleum products and more specifically concerns the acquisition of subsurface formation data such as formation pressure, formation permeability and the like while well drilling operations are in progress.
2. Description of the Related Art
In oil well description services, one part of the standard formation evaluation parameters is concerned with the reservoir pressure and the permeability of the reservoir rock. Present day operations obtain these parameters either through wireline logging via a "formation tester" tool or through drill stem tests. Both types of measurements are available in "open-hole" or "cased-hole" applications, and require a supplemental "trip", i.e., removing the drill string from the wellbore, running a formation tester into the wellbore to acquire the formation data and, after retrieving the formation tester, running the drill string back into the wellbore for further drilling. For the reason that "tripping the well" in this manner uses significant amounts of expensive rig time, it is typically done under circumstances where the formation data is absolutely needed or it is done when tripping of the drill string is done for a drill bit change or for other reasons.
During well drilling activities, the availability of reservoir formation data on a "real time" basis is a valuable asset. Real time formation pressure obtained while drilling will allow a drilling engineer or driller to make decisions concerning changes in drilling mud weight and composition as well as penetration parameters at a much earlier time to thus promote the safety aspects of drilling. The availability of real time reservoir formation data is also desirable to enable precision control of drill bit weight in relation to formation pressure changes and changes in permeability so that the drilling operation can be carried out at its maximum efficiency.
It is desirable therefore to provide a method and apparatus for well drilling that enable the acquisition of various formation data from a subsurface zone of interest while the drill string with its drill collars, drill bit and other drilling components are present within the well bore, thus eliminating or minimizing the need for tripping the well drilling equipment for the sole purpose of running formation testers into the wellbore for identification of these formation parameters. It is also desirable to provide a method and apparatus for well drilling that have the capability of acquiring formation data parameters such as pressure, temperature, and permeability, etc., while well drilling is in progress and to do so in connection with all known methods for borehole drilling.
To address these longfelt needs in the industry, it is a principal object of the present invention to provide a novel method and apparatus for acquiring subsurface formation data in connection with borehole drilling operations without necessitating tripping of the drill string from the well bore.
It is another object of the present invention to provide a novel method and apparatus for acquiring subsurface formation data during drilling operations.
It is an even further object of the present invention to provide a novel method and apparatus for acquiring subsurface formation data while drilling of a wellbore is in progress.
It is another object of the present invention to provide a novel method and apparatus for acquiring subsurface formation data by positioning a remote data sensor/transmitter within a subsurface formation adjacent a wellbore, selectively activating the remote data sensor for sensing, recording and transmitting formation data, and selectively receiving transmitted formation data by the drill stem system for display to drilling personnel.
It is an even further object of the present invention to provide such a novel method and apparatus by means of one or more remote "intelligent" formation data sensors that permits the transmission of formation data on a substantially real time basis to a data receiver in a drill collar or sonde that is a component of the drill string and has the capability of transmitting the received data through the drill string to surface equipment for display to drilling personnel.